I found a way to remove the purple center spot by using a VirtualDub filter. And probaly the anti-vignetting is going to work as well.
...
Then I used the Layer Filter by Brian Allen Vanderburg II to substract this correction layer file from the original frames.
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The result is quite nice! See samples below! It's not optimal yes: just 6 images from a ceiling.... But the effect is already quite descent.

I also experimented with removing the vignetting using this filter.
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I remember an anti-vignetting has been discussed in this thread, so probably I have to try this.

If I found an optimum filter set, it's easy to process all movies in a batch.

Pretty nice correction of the hot spot! I've not tried to use the levels filter, not really knowing what it could do.

The vignetting needs a stronger filter setting. There's also a third-party Vdub filter just for this called hotspot.vdf by Donald Graft. I've used it with pretty good results, but I found that the strength of the vignetting is not a constant. I.e., there is much less noticeable vignetting when the exposure level is very high (e.g. bright sun) and much stronger in low light. The hot spot effect also varies with light level. So one filter to fit all videos is not likely to produce as good results as having maybe three, one for low, medium, and high light levels. If a video has a lot of varying light levels, you might have to compromise with one filter anyway.

All-in-all, good sleuthing with freeware solutions!

Having said that, it's still a lot of work. For tasks like that, I found the MAGIX MEP17+ commercial editor a very good solution. I can use one filter (same .bmp I created for use with the Vdub Hotspot), and that editor can selectively vary not only brightness with the filters, but also the RGB colors.
And slicing the video where there's a big variation in brightness allows the filter to be reselected and adjusted for just the selected slice. Very powerful and fairly easy to use and adjust in real time preview once the control toggles are understood. But, it's a $65 solution with a learning curve attached, not free!

- 4.4V and less (e. g. dedicated car "charger"): V2 depletes the battery until its voltage reaches external voltage minus ~0.2V, and then it starts to use external power. For example, external 4.2V car charger starts to power the camera when battery depletes to about 10% of its capacity. Low risk, only in case of totally depleted battery there is a risk of overcurrent.

- 4.4V to 4.7V: V2 charges the internal battery forever. High risk of fast degradation of the battery. (Some people really complain about short battery live here.)

- 4.7V and more: Emergency breaker on the battery terminal disconnects it from the power. No charging or discharging happens.
...Unmodified V2 is not capable to correctly charge while recording.

When I am in car, I plug the camera to one of standard mini USBs plug of my universal 5V car power supply. The camera records and it is fully charged when removed from the car. (With the dedicated car "charger", my V2 camera was able to record about 2 minutes after removing from the car.)

Your #2 functions differently from mine. I just did a test starting with a fully charged camera battery and filled a 4GB flash card recording with my #2 connected to its dedicated car charger. I then plugged the camera into my PC USB port just long enough to erase the card, then immediately started a video with ONLY the internal battery powering the camera. I got a 35 min. recording... close to normal for my battery fully-charged condition.

Then starting with the internal battery depleted, I again wiped the card, plugged into my car charger, and began another recording sequence, filling the 4GB card again. After which I wiped the file from the card, and immediately started another recording without charging the battery from my PC USB port. That recording lasted just under 39 minutes, indicating the battery was fully charged while it was recording!

So it is clear to me that not ALL #2 cameras have the same charging issue that yours does.

One thing I noticed from your voltage measurements is the voltage levels you measured appear to be higher than normal (I assume they are accurate measurements). I may be mis-understanding your readings, but a properly functioning protection circuit board should clamp the upper voltage limit available to the battery at nominally 4.2V +/- going into the battery. Anything higher can damage the battery, or worse, cause it to over-heat, swell, and possibly ignite if the voltage gets too high. There are some representative tests to show this on the chucklohr.com web site for the similar #3 SD version of the camera.

Assuming the external power source has sufficient current available at the proper voltage, the parallel connection with the battery should work in unison, with external source doing most all of the work if the battery is fully charged, and taking up the slack as the internal battery starts to be depleted, keeping the battery charged in the process. A special charging circuit is not needed if the voltage levelat the battery terminals is clamped at a nominal 4.2V. A lipo cell will stay charged to the voltage level on it's terminals. I routinely charge up to 4 cells in parallel with my flight battery packs, with the charger maintaining a steady 4.2V on the charging connection for the latter half of the charge cycle.

Your #2 functions differently from mine. I just did a test starting with a fully charged camera battery and filled a 4GB flash card recording with my #2 connected to its dedicated car charger. I then plugged the camera into my PC USB port just long enough to erase the card, then immediately started a video with ONLY the internal battery powering the camera. I got a 35 min. recording... close to normal for my battery fully-charged condition.

Well, in this case my V2 camera behaves differently. After recording in the car with the dedicated car "charger", the battery is nearly completely depleted. After a 1 hour of driving, I am able to record only about 3 minutes of video with the internal battery.

Quote:

Originally Posted by Tom Frank

Then starting with the internal battery depleted, I again wiped the card, plugged into my car charger, and began another recording sequence, filling the 4GB card again. After which I wiped the file from the card, and immediately started another recording without charging the battery from my PC USB port. That recording lasted just under 39 minutes, indicating the battery was fully charged while it was recording!

So it is clear to me that not ALL #2 cameras have the same charging issue that yours does.

Yes, it looks so. Can you measure your car charger voltage? My dedicated "charger" provides 4.20V on pin 4, and my camera has a Schottky diode on pin 4 as the only part. By principle, the voltage on battery module can not raise above 4.02V. I measured there about 3.95V - i. e. far from fully charge.

Quote:

Originally Posted by Tom Frank

One thing I noticed from your voltage measurements is the voltage levels you measured appear to be higher than normal (I assume they are accurate measurements).

These voltages were provided by variable power supply connected to the pin 4 to test the camera behavior, not the dedicated charger. I wanted to test, how it can be charged better.

Sorry, they are not accurate. My old lab power supply was not stable enough and the camera significantly changes its power consumption depending on voltage. If you are interested, I can measure my camera again. Now I have a new equipment and I can measure accurately now.

Quote:

Originally Posted by Tom Frank

I may be mis-understanding your readings, but a properly functioning protection circuit board should clamp the upper voltage limit available to the battery at nominally 4.2V +/- going into the battery. Anything higher can damage the battery, or worse, cause it to over-heat, swell, and possibly ignite if the voltage gets too high. There are some representative tests to show this on the chucklohr.com web site for the similar #3 SD version of the camera.

There are two circuits in my camera - CC/CV charger IC that limits voltage to 4.2V and limits current. But it is used only if I power the camera from pin 1.

If I power the camera from pin 4, the only protection represents the breaker inside the battery. I can measure exact voltage when it breaks, but is is probably a bit more than 4.2V (4.3V?). Keep in mind, that the circuit inside the battery module is not intended as charging controller. It is a last resort damage protection.

I seen 5.5V and more on battery module terminals when powering via pin 4! So there is no other protection in my camera than the circuit inside the battery module.

Quote:

Originally Posted by Tom Frank

Assuming the external power source has sufficient current available at the proper voltage, the parallel connection with the battery should work in unison, with external source doing most all of the work if the battery is fully charged, and taking up the slack as the internal battery starts to be depleted, keeping the battery charged in the process. A special charging circuit is not needed if the voltage levelat the battery terminals is clamped at a nominal 4.2V. A lipo cell will stay charged to the voltage level on it's terminals. I routinely charge up to 4 cells in parallel with my flight battery packs, with the charger maintaining a steady 4.2V on the charging connection for the latter half of the charge cycle.

No, connecting any power supply in parallel with LiPol battery is always a bad design. Even with only 4.2V power supply, there is a risk of over-current when the battery is depleted.

...
...
No, connecting any power supply in parallel with LiPol battery is always a bad design. Even with only 4.2V power supply, there is a risk of over-current when the battery is depleted.

I always thought it was a bad idea to connect lipos in parallel...
However, after reading all the postings in this thread (good job I started early!), this seems to be what a lot of people do.

Early in 2010, while I was trying to find a way to power the #3 with an external power source, I was also told:
"... And connecting 2 lipo in parallel can also be a very bad idea."

So, I'm a bit , but common logic tells me that it is, indeed, not such a good idea to connect lipos in parallel. However, given the fact that the internal battery only lasts about 3 or 4 months (at least my last two didn't last any longer), I guess not too much harm can be done. On the other hand, perhaps my batteries don't last long because I always use the special cable - and as you say, there is no external regulation.
Since I always need long recording times, I'm forced to use external power supplies, and I'm sure your design will give me the extra protection. Now I just need the time to get the components/materials and make the board.

I love the #11 Jumbo camera, but it does not have an auto standby shutoff. So if the power button on the unit gets accidently pushed, it will boot up and sit there until the battery goes dead. I think my regular #11 would have shut off after a short period. Anybody know of a fix?
tnx,
Ken

I always thought it was a bad idea to connect lipos in parallel...
However, after reading all the postings in this thread (good job I started early!), this seems to be what a lot of people do.

Connecting of two cells that have actually exactly the same voltage is not as bad. (If they do not have the same voltage, the result depends on the circuit resistance - from nothing to melting of wires or explosion.)

If you are charging two cells in parallel, you do not you have control over the charging current and temperature of particular cells.

But here you connect external power supply with the LiPol battery (well, via a diode and an emergency breaker).

I love the #11 Jumbo camera, but it does not have an auto standby shutoff. So if the power button on the unit gets accidently pushed, it will boot up and sit there until the battery goes dead. I think my regular #11 would have shut off after a short period. Anybody know of a fix?
tnx,
Ken

Ken, aside from the difficulty in seeing the CHG/ AMBER ON LED in the new case unless you are looking directly down and over it.. I do like my No 11 Jumbo a lot too. and never worry as much any more about missing the action and the audio buzz as the std No 11's with half the battery life.. I may be misunderstanding what is going on with your Jumbo's regarding the auto Shutdown..when in idle awaiting the start of a new record session mine does wait with the AMBER LED ON a full minute yes.. but then the AMBER STBY LED goes out and the camera falls back to idle/OFF mode. JimS

I've been searching to see if this has been addressed. Sorry if this is a duplicate question.

I have two 808 #11 cameras. I've updated the firmware to remove the time on both. One works great. On the other camera, if I record a video lasting more than one minute or so and turn the camera off, no file is saved. If I leave the camera on and can connect to a computer before it turns off, I've been able to access files of 5 or 6 minutes in length.

Yes, it looks so. Can you measure your car charger voltage? My dedicated "charger" provides 4.20v on pin 4, and my camera has a schottky diode on pin 4 as the only part. By principle, the voltage on battery module can not raise above 4.02v. I measured there about 3.95v - i. E. Far from fully charge.

My first test sequence that yielded the 35 min. battery-only recording after the car charger power test was done with the car charger that came with the #2 camera. It has the mini-USB cable integrated into the car charger plug. I could not safely measure the voltage on pin #4 with this one due to the size of my voltmeter probes and no separate mating mini-USB connector available to access the pins. But others have tested the similar car chargers and reported elsewhere in this thread voltage on pin #4 similar to your measurement.

On my second test sequence I used the car charger that came with my Jumbo #11 to power the same small #11 used in the prior test. That car charger has a plug with no integrated cable. Instead it plugs into the car charge socket and has a standard 4 pin female USB plug, with two supplied cables... one being a two wire cable terminated with the special mini-USB plug for powering the camera while recording, and the other a standard 4 wire mini-USB cable for just charging the camera, I guess, via the normal voltage on Pin #1 through the camera's dedicated CC-CV charging IC. I was able to measure the voltage on JUST the charger plug (with no attached cable), and that outputs an even 5.0V between the two outer contacts, consistent with a standard USB plug. And I was able to check continuity on the two-wire special mini-USB plug, confirming that the +5V from the car charge plug normal USB pin#1 does, indeed, cross over to pin#4 on the mini-USB end. So this car charger supplies a full 5V to the camera! I don't know if the Jumbo circuit board has any other components to drop the voltage down futher, or just relies on the battery protection circuit board to clamp the excess voltage from reaching the battery terminals (but I will contact the developer to find out. I have used my 4 AAA cell NiMH external battery pack to power my #2 with no adverse results (yet!), and it delivers close to 5V to the camera when freshly charged.

I guess this newer charger cable could be used to power the camera from a computer while recording.

Quote:

Originally Posted by utx

...
There are two circuits in my camera - cc/cv charger ic that limits voltage to 4.2v and limits current. But it is used only if i power the camera from pin 1.

If i power the camera from pin 4, the only protection represents the breaker inside the battery. I can measure exact voltage when it breaks, but is is probably a bit more than 4.2v (4.3v?). Keep in mind, that the circuit inside the battery module is not intended as charging controller. It is a last resort damage protection.

Yes, I fully understand this! The protection circuit on a battery has been tested on a battery from the old 808 camera (results in chucklohr.com). Not the same battery, but I believe the protection circuit boards all function similarly. It brackets the voltage, chopping off excess voltage at slightly above 4.2V and chops off power for low voltage cutoff battery protection. down around 3.0V. But the LVC is never reached WHILE RECORDING, because the camera cannot operate at a voltage below approximately 3.6V. It will stop recording, save the file, then shut down. The LVC 3.0V trip would only be reached if the camera is left idle for a very long period, because the internal clock is kept powered while the camera is shut off. At any rate, if the camera stops recording at 3.6V, there is a slight voltage recovery in the lipo cell when the load is reduced. This has been measured on the old 808 battery test to be about 3.7V.

Quote:

Originally Posted by utx

...
no, connecting any power supply in parallel with lipol battery is always a bad design. Even with only 4.2v power supply, there is a risk of over-current when the battery is depleted.

Yes, I understand this, too. I did not mean to imply otherwise. When I connect my lipo flight packs in parallel prior to charging, I make sure they are within .1V of each other using a cell balancer, and they are charged and balanced with a dedicated lipo charger. The voltage surge when connecting lipos in this manner is well controlled and safe. If the resting voltage of the camera cell is about 3.7V after the battery gets low as mentioned above, this represents about 15% of the battery capacity still remaining in the cell. Not fully depleted, but low never the less. Connecting an external battery pack is best done with the internal cell fully charged, though I have done it with the camera having just shut down from a low battery voltage with no obvious problems.

Well, I am starting to suspect that there is only one V2 camera, but two versions of car charger:
- 5V (?): Fully charges the battery while driving but probably overcharges.
- powering one - 4.20V: Starts to power the camera when the battery is nearly depleted.

I have the second version of the car "charger".

Quote:

Originally Posted by Tom Frank

The protection circuit on a battery has been tested on a battery from the old 808 camera (results in chucklohr.com). Not the same battery, but I believe the protection circuit boards all function similarly. It brackets the voltage, chopping off excess voltage at slightly above 4.2V and chops off power for low voltage cutoff battery protection. down around 3.0V.

I measured behavior of pin 4 powering and tested the protection circuit with my new equipment.

The protection breaker activates when the voltage on battery terminals reaches 4.76V-4.88V and charging current 0.25A-0.33A. In that moment charging current drops abruptly to 0A. I am not sure whether it is current activated or voltage activated, but both values are unsafe for terminals of a fully charged battery. And yes, the breaker resets somewhere above 3V.

Pin 4 voltage reaches in that time 4.88V-5.00V. To be sure that the protection activated, I had to use at least 5.01V.

Powering pin 4 with 4.54V, the battery terminal reached 4.20V/0.03A. It means that everything above that voltage on pin 4 is unsafe.

If somebody built a special pin 4 cable to power the camera from USB:
- If USB provides 4.88V or less, your battery is overcharged forever and quickly dies.
- If your USB provides 5.01 or more, your battery is overcharged only for a limited time and dies less quickly.
- Using a standard silicon diode in the power line may improve things a bit. Two diodes in series should be safe even if USB provides 5.5V.

The emergency charger provides 5.624V without any load => it overcharges the battery. I stopped my experiment at 4.22V at battery terminals and 4.54V on the charger. Current was 19mA and slowly raised.

Well, I am starting to suspect that there is only one V2 camera, but two versions of car charger:
- 5V (?): Fully charges the battery while driving but probably overcharges.
- powering one - 4.20V: Starts to power the camera when the battery is nearly depleted.

I have the second version of the car "charger".

I measured behavior of pin 4 powering and tested the protection circuit with my new equipment.

The protection breaker activates when the voltage on battery terminals reaches 4.76V-4.88V and charging current 0.25A-0.33A. In that moment charging current drops abruptly to 0A. I am not sure whether it is current activated or voltage activated, but both values are unsafe for terminals of a fully charged battery. And yes, the breaker resets somewhere above 3V.

Pin 4 voltage reaches in that time 4.88V-5.00V. To be sure that the protection activated, I had to use at least 5.01V.

Powering pin 4 with 4.54V, the battery terminal reached 4.20V/0.03A. It means that everything above that voltage on pin 4 is unsafe.

If somebody built a special pin 4 cable to power the camera from USB:
- If USB provides 4.88V or less, your battery is overcharged forever and quickly dies.
- If your USB provides 5.01 or more, your battery is overcharged only for a limited time and dies less quickly.
- Using a standard silicon diode in the power line may improve things a bit. Two diodes in series should be safe even if USB provides 5.5V.

The emergency charger provides 5.624V without any load => it overcharges the battery. I stopped my experiment at 4.22V at battery terminals and 4.54V on the charger. Current was 19mA and slowly raised.

I think what we have is one camera V2, two versions of car charger, and MANY different voltages from the different battery protection circuit boards! Quality control and/or voltage control accuracy on these boards may not be very good. I have one from a battery that came on my first #11 camera, and lost half its capacity in less than a month. I may see if I can test it for functioning (if it's still good).

Ken, aside from the difficulty in seeing the CHG/ AMBER ON LED in the new case unless you are looking directly down and over it.. I do like my No 11 Jumbo a lot too. and never worry as much any more about missing the action and the audio buzz as the std No 11's with half the battery life.. I may be misunderstanding what is going on with your Jumbo's regarding the auto Shutdown..when in idle awaiting the start of a new record session mine does wait with the AMBER LED ON a full minute yes.. but then the AMBER STBY LED goes out and the camera falls back to idle/OFF mode. JimS

Jim - I drilled out the LED hole with a #51 drill... easy to see the LED's now. I've tested all 3 of my jumbo's and they all will stay on in standby mode (amber lite on) until the cows come home. I've sent an email off to Emma (eletoponline) to get her thoughts.
Ken